---
id: SubscriptionPeriod
name: SubscriptionPeriod
version: 1.0.0
identifier: subscriptionPeriodId
summary: Represents a single billing cycle or interval within a subscription's lifetime.

properties:
  - name: subscriptionPeriodId
    type: UUID
    required: true
    description: Unique identifier for this specific subscription period.
  - name: subscriptionId
    type: UUID
    required: true
    description: Identifier of the parent Subscription this period belongs to.
  - name: planId # Denormalized for easier lookup?
    type: UUID
    required: true
    description: Identifier of the Plan active during this period
  - name: startDate
    type: Date
    required: true
    description: The start date of this billing period.
  - name: endDate
    type: Date
    required: true
    description: The end date of this billing period.
  - name: invoiceId # Optional, links to the invoice generated for this period
    type: UUID
    required: false
    description: Identifier of the invoice created for this period's charge.
  - name: paymentId # Optional, links to the payment made for this period's invoice
    type: UUID
    required: false
    description: Identifier of the payment that settled the invoice for this period.
  - name: status
    type: string # (e.g., Active, Billed, Paid, Unpaid, PastDue)
    required: true
    description: Status specific to this period (reflects invoicing/payment state).
  - name: amountBilled
    type: decimal
    required: false # May only be set once invoiced
    description: The actual amount billed for this period (could differ from plan due to promotions, usage, etc.).
  - name: currency
    type: string # ISO 4217 code
    required: false
    description: Currency of the billed amount.
  - name: createdAt
    type: DateTime
    required: true
    description: Timestamp when this period record was created (often at the start of the period).
---

## Overview

The SubscriptionPeriod entity tracks the state and details of a specific billing cycle within a `Subscription`. It links the subscription to the relevant invoice and payment for that interval and records the exact dates and amount billed.

### Entity Properties
<EntityPropertiesTable />

## Relationships

*   **Subscription:** A subscription period belongs to one `Subscription`.
*   **Plan:** Reflects the `Plan` active during this period.
*   **Invoice:** May be associated with one `Invoice` generated for this period.
*   **Payment:** May be associated with one `Payment` that settled the period's invoice.

## Examples

*   Period for Jane Doe's 'Pro Plan' from 2024-05-01 to 2024-05-31, invoiced via #INV-00123, status Paid.
*   Period for Acme Corp's 'Enterprise Plan' from 2024-04-15 to 2024-05-14, status Billed, awaiting payment.
*   The first period (trial) for a new subscription from 2024-05-20 to 2024-06-19, status Active, amountBilled $0.00. 